you are correct in that no developers pulls those feeds from the house to the street now in Vegas. However, there are a lot of older homes that may not meet that criteria. Especially homes and neighborhoods from the 70's and 80's. Even as late as when Prime Cable was running Las Vegas, this was not always the case, but now that Cox bought the local market, they insist on running the lines to the home of any new buildings.
There is talk of the 8300 coming to Cox, but not for a while. I wouldn't expect to see it this year in Vegas, although It may be tested
by someone before then, if I get lucky. Right now, I think SA has stopped production of the 8000 and is pushing the 8300 as a home media option. Phoenix has delayed their 8000 launch and their inventory is coming here and other regional Cox markets. They will probably launch the 8300 there a bit later. Cox is getting close to year end financials that will probably inhibit any major purchases until the new year.
As for the 8000, the passthrough feature is still in testing in Las Vegas, but it has it's issues. For now, enable all the resolutions you want in the Set-up menu, then pick the output you want for a particular show. I use 480i out to watch the Scifi Channel so that my TV will use it's film mode, anti-aliasing and noise reduction circuitry and I can also use my own stretch or zoom modes.